Semi-automatic rifles and carbines allow multiple cartridges to be fired in a short period of time by simply pulling the trigger as many times as shots are to be fired. The only limitation on the number of rounds fired is the number of cartridges that the weapon will hold in its magazine.
One example of such a semi-automatic carbine is the Soviet designed SKS carbine. This weapon, once a standard in the Soviet army, is also utilized by many European and Asian countries. Carbines of East German, the People's Republic of China, North Korean and Yugoslavian manufacture are currently available in the U.S. marketplace under various designations.
The SKS type carbine has a stock with a vertical through-hole adapted to receive and be covered at its top by a barrel and receiver, at its rear underside by a trigger mechanism, and at its forward underside by the original-equipment magazine. The original-equipment magazine of the firearm has a "clamshell" configuration utilizing a pair of magazine halves connected at a forward pivot site. The upper half of the original-equipment magazine is retained within the stock by various components. The lower half of the original-equipment magazine pivots to allow its interior to be accessed for unloading purposes, cleaning purposes, or the like. A spring-biased magazine retaining latch supported on the trigger mechanism engages a rear portion of the lower half of the original-equipment magazine to retain the original-equipment magazine in a closed configuration during use. Manual sliding of the spring-biased magazine retaining latch rearwardly allows the lower half of the original-equipment magazine to pivot downwardly, thereby opening the magazine.
The original-equipment, clamshell magazine of this weapon holds ten cartridges but is not designed to allow rapid reloading of the rifle. The original-equipment magazine engages a forward fixed attachment site and is secured within the firearm by the trigger mechanism. This prevents the removal of the magazine without the prior removal of the trigger mechanism and thus prohibits the use of preloaded replacement magazines for rapid reloading. Instead, it is necessary to manually reload the original-equipment magazine each time it becomes empty. This is tedious and can create danger for a soldier in a battle setting where it is often desirable to fire more than ten rounds in rapid succession.
Box-type replacement magazines for other weapons are known in the prior art. They provide a source of additional cartridges in the form of preloaded magazines for the associated firearms. Examples of box magazines are disclosed in U.S. Pat. Nos. 1,407,633; 2,081,235; 2,185,676; 3,676,946; and 4,864,758.
My co-pending U.S. patent application Ser. No. 07/553,827 discloses a readily detachable, externally loadable, box magazine adapted to replace the original-equipment box magazine of the SKS type firearm. This replacement magazine includes an elongated extension section attached at one end to the top of the magazine and projecting forwardly therefrom. The extension section is configured to position a forward latch projection from the magazine to engage the same fixed attachment site of the firearm which retains the forward end of the original-equipment magazine. A rear latch projection attached to the rear of the magazine is configured to engage the spring-biased retaining latch of the firearm which is provided to act as a catch for the lower half of the original-equipment magazine. In this manner, the readily detachable magazine utilizes the existing structure of the firearm, but can be removed without disassembly of the firearm.
The readily detachable magazine of my co-pending application may be secured to the firearm by engaging the fixed attachment site and the spring-biased retaining latch of the firearm, and may be removed by disengaging the spring-biased retaining latch of the firearm from the rear latch projection. Further, the extension section substantially covers the underside portion of the stock through-hole forward of the hollow body when the magazine is attached to the firearm. This protects the internal firearm components from damage.
While the magazine disclosed in my co-pending U.S. patent application has enjoyed considerable commercial success, it has obvious disadvantages. In particular, the magazine must be especially manufactured for use with the SKS carbine. Obviously, such a specially manufactured magazine cannot be interchangeably used on other types of weapons. Furthermore, the elongated extension section of the magazine adds considerably to the bulk of the magazine when it is out of the carbine, giving the magazine an awkward configuration for storage.
It would be highly desirable to be able to use a standard box magazine in an SKS carbine, particularly if the standard box magazine could be readily attached to and detached from the weapon. It would also be highly desirable if the rifle used a standard box magazine could be used in other types of rifles and carbines. It would also be highly desirable if a box magazine used in the SKS carbine did not have to be modified so as to present storage problems.